Effervescent analgesic antacid compositions containing acetylsalicylic acid as the analgesic component and citric acid and sodium bicarbonate as the principal ingredients of an effervescent couple have been known for many years. One of the disadvantages of these compositions is the elevated sodium content which renders them unsuitable for individuals who should reduce their sodium intake. While efforts have been made in the prior art to produce such compositions having reduced sodium content by including calcium carbonate and potassium bicarbonate, for example, the resulting products form solutions that have an unpleasant taste. When acetaminophen, which has an unpleasant taste itself, is used to replace all or a part of the acetylsalicylic acid as the analgesic component, the resulting product has been generally unacceptable from a taste standpoint.
Another problem with prior art effervescent analgesic antacid compositions having reduced sodium content is that they do not completely dissolve. They form a cloudy or milky solution with a scum of undissolved particles floating on the surface of the liquid.
Ketoprofen is another analgesic compound that is suitable for use in an effervescent analgesic antacid composition.
There is thus a need for an effervescent analgesic antacid composition containing acetylsalicylic acid, acetaminophen, ketoprofen or mixtures thereof as the analgesic component and reduced sodium content in the effervescent couple/antacid component which forms a solution that is pleasant tasting. There is also a need for such composition that will substantially completely dissolve in water to form a clear solution with no scum on the liquid surface.
U.S. Pat. No. 3,495,001 discloses a sodium-free effervescent analgesic composition. U.S. Pat. Nos. 2,854,377; 2,953,459; 2,985,562; 3,102,075; 3,105,792; 3,136,692; 3,243,377; 3,518,343; 3,903,255; and 4,093,710 disclose various effervescent compositions containing various amounts and combinations of glycine, surfactants such as dioctyl sodium sulfosuccinate, fumaric acid and polyvinyl pyrrolidone. I. R. Mohrle, "Pharmaceutical Dosage Forms: Tablets", Vol. 1, Marcel Dekker, Inc., New York, NY, pp. 225-258 (1980) provides a full description of various effervescent tablet formulations and their ingredients. U.S. Pat. No. 4,704,269 discloses an effervescent analgesic antacid composition having reduced sodium content wherein the antacid and a food grade acid reactive therewith to form the effervescent couple are in the form of an agglomerate held together by a water soluble food grade binder.
None of the above prior art disclosures specifically disclose or suggest the novel compositions of the present invention.